In typical completions in the past, metallic screens have been inserted on rigid or coiled tubing into a zone in the wellbore for production. Prior to producing the zone, sand particles were delivered outside the screen in a technique known as gravel packing. Screens have also been used that come prepacked with a sand layer as an alternative to the traditional gravel packing techniques or to be used in conjunction with the placement of sand outside the screen. The gravel packing procedures especially in horizontal completions left uncertainties as to whether the sand had been sufficiently distributed uniformly in the annular space so as to provide an effective gravel pack. Additionally, the gravel packing procedure took valuable time to accomplish and required the use of surface equipment to handle the material for placement in the wellbore. Another disadvantage of traditional gravel packing procedures is that an annular space around the screen had to be left so that the gravel could be placed there. The end result was the inside diameter within the screen was necessarily small to allow for the presence of the annular space. This constriction in size could also adversely affect the production of the formation to the surface.
In using certain drilling techniques, particularly in unconsolidated formations, the drilling mud would form a barrier adjacent the wellbore which cause subsequent plugging when the production began, even with screens and gravel packs being deployed.
A more ideal situation for producing a formation is to leave the wellbore in its drilled state so as to create the least amount of disturbance to the formation which has just been drilled. Traditional techniques leaving an annular gap which would be gravel packed, further involved risks of damaging the formation in the gravel packing process, such as when situations occurred that would allow fluid to convey the gravel to also apply hydraulic forces on the formation as well as incompatibilities between the formation and the fluids used to convey the gravel.